Process for the upgrading of cellulose textiles



United States Patent Oil ice 3,095,323 PROCESS FOR THE UPGRADING F CELLULOSE TEXTILES Hermann Behncke, Frankfurt am Main, Germany, assignor to Inventa A.G. fiir Forschung und Patentverwertung, Zurich, Switzerland No Drawing. Filed Sept. 22, 1960, Ser. No. 57,644 Claims priority, application Switzerland Oct. 3, 1959 2 Claims. (Cl. 117-143) The invention relates to a new finishing agent for cellulosic textiles and its application thereto.

Numerous processes are known which facilitate imparting several advantageous properties of fully synthetic fibers to woven or knitted textiles consisting of native or regenerated cellulose. For instance, by suitable finishing with resins, the crease resistance, shrinking, swelling in water and soiling of cellulosic textiles can be favorably influenced. Ideal finishing agents are supposed not only to impart to these textiles the advantageous properties of synthetic fibers, but also to maintain simultaneously the advantages of vegetable fibers, such as good dyeability, adsorption of perspiration and breathability.

The principal finishing agents to date have been those resins or resin bases, respectively, which are applied in aqueous solution or suspension and which can be hardened, by means of acid or acid-forming catalysts, into higher-molecular substances which cannot be washed out or, at least, are very difiicult to wash out. Primarily the carbamide resins have been used, e.g., resin of the type urea-formaldehyde, melamine-formaldehyde or ethylene urea-formaldehyde.

Finishing of textiles with these agents, most of all, has the following disadvantages: Primarily due to the use of acid hardening catalysts, a considerable decrease in the tear-resistance must be accepted. Through the coating of the fibers with the resin, the stretch, elasticity, hand and scrubbability of the fibers also suffer. It is said that the addition of plasticizers eliminates some of these drawbacks, especially the brittleness of the fibers, however, the break elasticity thereby is decreased. Furthermore, the fact must be considered that the plasticizer is washed out of the fiber or of the impregnant upon repeated washings of the textile.

It is for these reasons that finishing of cellulosic textiles has become an involved process. The choice of a suitable resin, hardener and plasticizer, and, most of all, the correct dosage of these components meet with difliculties even for the expert, and he does not always succeed in attaining the desired finishing efiect without incurring one or the other of the drawbacks named above.

It is the object of the invention to provide a novel finishing agent for cellulos-ic fibers and textiles made thereof which is based on urea and which imparts to these materials the desired properties of the fully synthetic products, such as, e.g., crease resistance and fast drying, without promoting disadvantageous effects, and which is easily and simply applied.

It has been found that cellulosic textiles can be finished in a particularly advantageous manner with a wash-resistant synthetic resin formed of w-carboxyalkylene-urea molecules.

Because of the carboxyl group present in the molecule, no acid hardening or polymerization catalysts, damaging to the properties of the textiles, need be added to these w-carboxy-alkyleneureas (urea-fatty acids), such as ureacaproic acid, NH C-O-NH(CH COOH, or ureaundecanoic acid, NH CONH(CH -COOH. These urea-fatty acids not only are self-polymerizing, but also can effect the hardening of the known carba-mide resin finishing agents, or their precondensates, respectively, such as urea-formaldehyde, melamine-formaldehyde or 3,095,323 Patented June 25, 1963 ethylene urea-formaldehyde, in lieu of .the hitherto used acid catalysts, such as zinc chloride, magnesium chloride, ammonium chloride, or others.

A. further advantage of the urea-fatty acids according to the invention resides in the fact that they exert no unfavorable influence on the hand nor on the elasticity properties of the textile substrates so that the addition of a plasticizer becomes unnecessary. The cause of these phenomena probably is the chain-like construction of the urea-fatty acid molecules, similar to those of polyamides, so that they are better suited than, for instance, ureaformaldehyde resins, having no chain structure, to impart the properties of fully synthetic fiber products to other textiles.

Investigations have proven that not only the crease recovery angle and the tensile strength of textiles finished with the urea-fatty acids according to the invention is favorably influenced, but also that the water absorbability largely remains (it is percent as compared with unfinished material which is percent), and that even so the thus finished material, when hung up wet, dries faster than the same material unfinished. While an unfinished cotton tricot releases moisture down to 4 percent, when hung in a climate-controlled room, within 160 minutes, the same material, after finishing according to the invention, releases the moisture down to 4 percent under identical conditions within minutes.

The application and effects attained by finishing textiles according to the invention now will be further illustrated by the following examples. However, it should be understood that these are given merely by way of explanation, not of limitation, and that numerous changes may be made in the details without departing from the spirit and the scope of the invention as hereinafter claimed.

Example I parts by weight ureacaproic acid are dissolved in 1,000 parts water with addition of a little aqueous ammonia. A mercerized, desized woven cotton is. immersed and saturated therein at 18 C., fulled and then predried for 15 minutes at 80 C. Finally, the textile is heated on a stretcher framer for approximately 10 minutes at 160-165 C.

After hanging the thus finished textile up in a climatecontrolled room, it is washed and shows, after drying, a good crease resistance. The crease recovery angle in the warp is 108, in the fill 94. Untreated cotton, by comparison, has a crease recovery angle of 64 and 60, respectively.

Example 2 160 parts by weight ureaundecanoic acid are dissolved or emulsified, respectively, in 1,000 parts water with addi- .tion of a little aqueous ammonia. Mercerized, desized woven cotton is immersed and saturated therein at 18, fulled and then predried at 80 C. for 15 minutes. The woven clot-h then is heated on a stretcher frame at C. for approximately 10 minutes to set the impregnant.

After hanging the thus. finished textile in a climatecontrolled room, the dry material has good crease resistance. The crease recovery angle is 110 in the warp, 100 in the fill.

Example 3 80 parts by weight ureacaproic acid are dissolved in 1,000 parts water with addition of a little aqueous ammonia and then 80 parts by weight of a melamine- -forrnaldehyde precondensate are dissolved therein. A mercerized, desized woven cotton textile is immersed and saturated therein at 18 C., fulled and predried at 80 C. for 15 minutes. The textile then is heated on a stretcher frame for approximatley 10 minutes at 160-165 C. to harden and set the impregnant.

After hanging up the thus treated textile in a climatecontrolled room, it is washed. After drying, it exhibits good crease resistance with a crease recovery angle for the warp of 105 and for the fill of 108.

The tear resistance has not decreased as strongly as in the case of using the customary hardening catalysts, e.g., ammonium chloride, zinc chloride, magnesium chloride or diammonium phosphate. Whereas in the case of using the latter catalysts, while attaining a good crease resistance, the tear resistance drops by more than 35 percent and up to 50 percent, in the instance of the above example, using urea-fatty acids, the decrease in tear resistance is no higher than 24-25 percent.

I claim as my invention:

1. A process for the upgrading of cellulosic textiles, which comprises impregnating said textiles with a self- 4 polymerizing w-carboxylalkyleneurea, having an alkylene group consisting of 5 to 10 methylene groups, in aqueous solution, hardening and drying said resin.

2. A process for the upgrading of cellulosic textiles, which comprises impregnating said textiles with a mixture of precondensates of carbamide resins with self-polymerizing w-carboxylalkyleneureas, having an alkylene group consisting of 5 to 10 methylene groups, in aqueous solution, said w-carboxylalkyleneureas simultaneously acting as hardening catalysts for said carbamide resins, thus obviating the need for an addition of acid hardening catalysts, and hardening and drying said mixture.

References Cited in the file of this patent UNITED STATES PATENTS Bruson Feb. 5, 1935 

1. A PROCESS FOR THE UPGRADING OF CELLULOSIC TEXTILES, WHICH COMPRISES IMPREGNATING SAID TEXTILES WITH A SELFPOLYMERIZING W-CARBOXYLALKYLENEUREA, HAVING AN ALKYLENE GROUP CONSISTING OF 5 TO 10 METHYLENE GROUPS, IN AQUEOUS SOLUTION HARDENING AND DRYING SAID RESIN. 